A randomly generated password contains four characters. Each of the four characters is either a lowercase letter or a digit from
0–9. Each character in the password cannot be used more than once. What is the approximate probability that exactly one of the four characters will be a number?
The answer is 800. To find this, multiply 10 times 8 to find the number you are dividing. (80) now, multiply 80 by 10. (800) 1/10 of 800 is 80, which is ten times as much as 8.
